[The determination of diphtheria toxin in circulating immune complexes]

A method for measuring the level of diphtheria toxin in the circulating immune complexes is proposed, making use of monoclonal antibodies to COOH-terminal site of the toxin molecule. The levels of diphtheria toxin were measured in children with different clinical forms of oropharyngeal diphtheria. Levels and time course of toxin for each clinical forms have been defined. The studies demonstrated the specificity of the method and its efficacy for rapid diagnosis of diphtheria.